Ladder roller mounting



y 'E. VON BOLHAR I I LADDER ROLLER MOUNTINQ' 2 Sheets-Sheet 1 Filed April 29, 1947 y 26, 1949- E. VON BOLHAR LADDER ROLLER MOUNTING 2 Sheets-Sheet 2 Filed April 29, 1947 INVENTOR. fayar V0 (yo/haw BY Patented July 26, 1949 2,477,22f1f f. LADDER ROLLER VMOUNQTITNGI .Edgarvon Bolhar,:.Sausalito,aalif., assignor to one. Manufacturing Company, San .Francisco,

Calif., a corporation of California Application April--29, l94'7 Serial No. '-74'4,60'7

My invention relates generally to the :construction of alluvial dredges which incorporate a ging ladder amounting in effect to a boomhaving a lower tumbler at one ez:d,1and an upperidriving tumbler at the other end. Trained aroundxthe tumblers and driven by the upperone, is an endless chain comprised primarily of dredgin 'buckets effective to dislodge the/earth and to carry'it along the ladder to ultimate discharge. To :suppo rt the upper run of digging-buckets between the lower and upper tumblers, a number of transverse cylindrical :rollers are disposed onv the :ladder in positions to support the chainlike. bucket portions contacting them. .The;rollers cany the weight of the buckets andof their load ingreater or less degreedepending upon the angularity of the ladder. Asthis changes durin a dredging operation the load "upon :therollers likewise changes. In addition; 'thelength of the linksin-. cluded in the bucket chain is relatively great with regard to the diameter .of the cylindricaLlower tumbler. Due to. the tangent angularityof the links as they pass around theilower tumbler, the lower portion of the bucket chain especially on the upper, conveying side'is alternately liftedand lowered. This produces an undulatory or slapping action of the lower portion ofthe bucket chainso that the rollers most nearlyadjacentthe lower tumbler are subjected to pounding :forces due to this cause. i

It istherefore an object of my invention to provide a ladder roller mounting effective iito withstand the various loads and: intermittent shocks imposed upon it .duringidredging ope ations.

Another object of'my invention'isto provide a ladder roller mounting .of improved construction for, longer life and more satisfactory vsci-vice. A further object of the invention is to provide a ladder roller mounting effective to absorber cushion some of the Shocks imposed upon it with out transmitting them to the supporting ladder and appurtenant mechanisms;

An additional object of the invention 1$ to provide a ladder roller mounting which is virtually interchangeable with mountings of the present standard design, and, in addition, is effective to absorb shocks,

An additional object of the invention ls topmvide a ladder roller mounting capable 'ofabsorbing shocks yet efiective to maintain satisfactorily the alignment and position of the ladder roller.

Other objects, together with the foregoing, are attained in the embodiment of the invention-described in the following description and illustrated in the accompanying drawings-inwhich Figure 1 is a side elevation of'a oithe lower end of a digging ladder and attendant dredge bucket chain, showing the parts in posl tion for dredging operation and i11u'strating the Claims. (crease-.26

2 use oi the ladder'roller anounting of any-invention. l

-Figure '2 is constructed in accordance with my invention, the central section of the structure being broken away to reducethe extent ofthe figure-nude 7 portion of a bushing and boss for :a pin being s'hownin cross-section.

*Figu ne -3-isLa :cross section, the plane'of which is indicated by the -line. 3- 3 of Figure 2.

Figure 4 is 5 across section the. plane of i which is indicated byithe lined-4 ofiFig-nre 2. v Figure; 5' is anlisometric perspective of a. bushingintilized-in connection withrny ladder roller mounting certain ipcrtions; of :the .bushingbeing shown insection, the: planesiof section beingboth horizontal: and vertical and extending longitudinally of the bushing.

:zimits preferred ronnttheiaduerrciierlmcunt- :of .myrinvention is; for use on .a dredging dadder, and;in 'connectionnwith aastandarddadder roller havingbearings onitsoppositetendsl Each. roller end is provided withone of theanountinga Iihe mounting includes .abasaprsaddle, adapte to be secured to the ladder and is formed @withla pairgof bosses, arranged with their axesjparallel totheaxis otthelad-der roller and encompassing cylindrical deformable bushlngs,,, for example metal vlined rulraber bushings. ,-.Piercing-, the Pair f h slune x mo nt d s p r. of pinsproiecting on opposite sides of the bosses and attheir eud se a iua a mss ed ns lat ly-dr m the.

sides; of a j ournal-capable of receiving the bearne nd -9 l e e Jou nal-lend thearms to et on t t ac a l ii -pa fitt nawit in deoressed central por on i h se d 1 pwhile theladcler roller mounting of myt invention can be niw o r di r um rces ni eren forms depending upongthe particular type of dredge vwitnlw h ittis .in udedtand d end upon theenvironment and engineering considerationsaccording to =;which itis ntilized, it has been successfully embodied asshown: herein whereinit takes the. place of rigid; ladder roller, mountings.-

I-nqthis environment there is provided digging ladderi6,,only. thelower end of .=which is shown. A generally cylindricaldower tumbler :l is mounted'in abearing structure Sat the lowerend entire ladder. Trained around the lower tumbler is a bucket chain-generailydesignated 9 comprised of a'piluralityof-linlcsll connectedbypins 12 to adjacent-hunks for ready --articu-lation, and carrying d'igging'buckets l3. r 1 7' v I i -As the chain 5 isadvanced-clcckwisearound the lower tmnbler I, the-digging buckets l3 engage withabank M tobe excavated and carry-a to appropriate further handling mechanisms;

Thelengthofthe links ii, that is thedlstance between the successive pins I 42 as the buckets 43 round the lower tumbler is suohthat they cca-plan of a ladder roller mounting alternately as they round the lower tumbler.

They thus approach and recede from the upper surface of the ladder 1 during the digg p tion and when they are not only under tension due to the driving force, but likewise are loaded with excavated material. This produces a severe problem especially in the lower supporting ladder rollers 2| which engage with the lower faces of the links and transmit the load and stresses to the ladder 6.

To avoid transmitting all of the strains, especially those due to impact and vibration, my ladder rollerrmounting is provided. Each roller 2|, especially as shown in Figures 2, 3, and 4, is a circular cylinder substantially identical at its opposite ends. Each end of the roller 2| is provided with a shaft 22 constituting a bearing. The shaft or bearing 22 is rotatably disposed within a sleeve 24 to constitute a journal. Lubrication to lubricant grooves 26 is supplied through a conduit 27. The sleeve 24 is provided with an out turned flange 28 against which a thrust washer 29 is disposed. A split collar 3| also engages the thrust washer and is clamped into a groove 32 turned in a reduced portion 33 of the shaft 22 so that the shaft and the roller 2| are axially accurately located with respect to the thrust washer 29.

Serving as a support for the sleeve 24 and the thrust washer 29 is a cradle generally designated 34 centrally bored to receive the sleeve 24 and having an outboard flange 36 to which a flanged cap 31 is secured by fastenings 38. The thrust washer 29 is clamped between the flange 36 and the cap 31. I

In order to retain the lubricant in the journal and to preclude the entrance of foreign matter and water, the end of the roller 2| is finished with a radial face 4| against which presses a packing ring 42 recessed in an annular groove 43 formed in one end of the cradle 34. A lip 44 overhangs a part of the recessed roller 2| to afford protection against falling rock or coarse gravel. The construction of the seal ring 42 and its attendant structure is included in more dotail and is claimed in my co-pending application entitled Shaft seal, filed May 27, 1947, with Serial Number 750,736, and assigned to the-assignee of the present application.

With the structure as so far described all of the loads and shocks and impacts imposed upon the roller 2| are correspondingly transmitted to the cradle 34 through the journal. It is in accordance with my invention that mechanism be provided for absorbing or preventing transmission of at least some of these stresses and shocks. For that reason, the cradle 34 is integrally formed with a pair of arms 46 and 41 on one side of the central axis 48 of the roller 2|, and a similar pair of arms 49 and on the other side of the axis 48. The arms of each pair extend substantially in a transverse plane from the central journal portion of the cradle and are pierced by bores to receive a pin 52 arranged with its axis 53 parallel to the axis 48. The pin projects beyond the arms 46 and 41 and is removably held in position by locking pins 54 and 56.

Surrounding the pin 52 is an internal metallic liner 5'l forming part of a deformable bu hing 58. The liner 57 is substantially 0f the same length as the space between the arms 46 and 41 so that the bushing is accurately located therebetween and isa sliding fit on the pin 52. Formed in intimate relation with the sleeve 51 is the surrounding bushing envelope of a deformable material, for example rubber. This envelope is inwardly beveled at its opposite ends and is likewise provided with a central channel 59 to afford room for displaced or deformed rubber. In many instances the central channel 59 or the end bevels, or'both, can be omitted if the flow or deformation of the rubber is not great. The outside of the envelope 58 is received with a push fit'within the bore of a boss 6| located between the arms 4-6 and 41, for example.

The boss 6| is one of a pair, the other boss 62 beingdisposed on the oppositesideof the axis 48. The. two bosses 6| and ;62 are considered as integral'parts of a saddle generally designated 63. This is :preferably a symmetrical casting having a depressed central portion 64 to underlie the journal 34.- At either side of the depression, the bosses SI and 62 are disposed with their axes parallel to and substantially the same transverse plane as the axes of the pins 52 and of the shaft 2|. 7

The. saddle also includes -a lower peripheral flange '66 through. which pass fastenings 6! for securing the saddle and correspondingly the entire mounting structure ontothe upper surface of the ladder 6. The arrangement is often such that the flange '66 and fastenings 61 engage the same portions of the ladder 6 that previously were engaged-by former, rigid roller mounts just as the journal 34 engages the shaft 22. in the same fashion as a rigid mount. In this Way, the present mounting is entirely interchangeable with previous rigid mounts.

With the present ladder roller mounting, the saddle 63 is rigid with the ladder -6 and the cradle 34 is rigid, except for rotation, with the roller 2|. But the saddle and cradle are not rigid with respect to each other. The four bushings 58 are effective to absorb shocks which normally would be transmitted between the saddle and the cradle. The mounting and location of the bushings are such that while the roller 2| is held-in accurate alignment with the ladder and is held against undue end shift, yet it is capable of yielding momentarily under impacts and other stresses which would normally be productive of extreme wear. The rubber bushings are also effective to absorb numerous rapid vibrations and thus assist in precluding the general shaking and loosening of fastenings which might otherwise occur.-

, The rollers 2| can. readily be renewed when worn since withdrawal of the pins 52 after removal of the fastenings 54 and 56 is readily accomplished,- and'the journals can equally well be renewed or. replaced if desired. If eventually the rubber, bushings are in deteriorated condi tion they too can readily be changed simply by withdrawing them and inserting new ones in their place.

' In general there has been provided in accordance with my invention a ladder roller mounting which can be interchanged with mountings already in use, which absorbs shocks and vibrations, which does not unduly transmit the slapping. of the upperlrun of the dredge bucket belt to the ladder, yet maintains the alignment of the bucket chain supporting rollers, and which permits-the replacement of the various parts with- I claim:

1. A ladder roller mounting comprising a saddle, a pair of bosses on said saddle, deformable bushings within said bosses, pins passing through said bushings, a cradle, arms extending from said cradle and engaging opposite ends of said pins, and a journal included in said cradle.

2. A ladder roller mounting comprising a saddle, a pair of cylindrical bosses disposed on said saddle with their axes parallel, deformable bushings within said bosses, pins passing through said bushings, a cradle, pairs of armseXtendin-g from opposite sides of said cradle, the arms of each of said pairs engaging the opposite ends of one of said pins, and a journal included in said cradle with its axis parallel to the axes of said pins.

3. A ladder roller mounting comprising a saddle having a depressed central portion, a pair of cylindrical bosses disposed at opposite sides of said central portion, deformable bushings Within said bosses, pins passing through said bushings, a cradle, pairs of arms extending from opposite sides of said cradle and engaging said pins, and a journal included in said cradle and extending into the central portion of said saddle.

2 4. A ladder roller mounting comprising a saddle having a depressed central portion, a pair of cylindrical bosses integral with said central portion and disposed on opposite sides thereof with their axes parallel, deformable bushings Within said bosses, pins passing through said bushings, a cradle, a journal included in said cradle and extending into the central portion of said saddle with its axis parallel to the axes of said pins, and arms integral with said journal engaging the ends of said pins.

5. A ladder roller mounting comprising a base element adapted to be secured to a ladder, a journal element adapted to receive a roller, a pair of bosses on one of said elements, deformable bushings in said bosses, pins passing through said bushings, and a plurality of pairs of arms on the other of said elements, each of said pairs of arms engaging a respective one of said pins.

EDGAR VON BOLHAR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 5 Number Name Date 1,978,939 Guy Oct. 30, 1934 2,043,725 Anderson June 9, 1936 

